Materials Data on KAsSe2 by Materials Project
KAsSe2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of K–Se bond distances ranging from 3.28–3.76 Å. In the second K1+ site, K1+ is bonded to six Se2- atoms to form distorted corner-sharing KSe6 pentagonal pyramids. There are a spread of K–Se bond distances ranging from 3.49–3.66 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of K–Se bond distances ranging from 3.28–3.76 Å. In the fourth K1+ site, K1+ is bonded to six Se2- atoms to form distorted corner-sharing KSe6 pentagonal pyramids. There are a spread of K–Se bond distances ranging from 3.49–3.66 Å. There are four inequivalent As3+ sites. In the first As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.35 Å) and two longer (2.49 Å) As–Se bond lengths. In the second As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.34–2.50 Å. In the third As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.35 Å) and two longer (2.49 Å) As–Se bond lengths. In the fourth As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.34–2.50 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to four K1+ and one As3+ atom. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to two K1+ and two As3+ atoms. In the third Se2- site, Se2- is bonded to four K1+ and one As3+ atom to form distorted SeK4As square pyramids that share corners with five SeK4As square pyramids and edges with three SeK3As2 square pyramids. In the fourth Se2- site, Se2- is bonded to three K1+ and two As3+ atoms to form a mixture of distorted corner and edge-sharing SeK3As2 square pyramids. In the fifth Se2- site, Se2- is bonded in a 5-coordinate geometry to four K1+ and one As3+ atom. In the sixth Se2- site, Se2- is bonded in a 4-coordinate geometry to two K1+ and two As3+ atoms. In the seventh Se2- site, Se2- is bonded to four K1+ and one As3+ atom to form distorted SeK4As square pyramids that share corners with five SeK4As square pyramids and edges with three SeK3As2 square pyramids. In the eighth Se2- site, Se2- is bonded to three K1+ and two As3+ atoms to form a mixture of distorted corner and edge-sharing SeK3As2 square pyramids.